//===--- ArgsToFrontendInputsConverter.h ------------------------*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

#ifndef POLARPHP_FRONTEND_ARGSTOFRONTENDINPUTSCONVERTER_H
#define POLARPHP_FRONTEND_ARGSTOFRONTENDINPUTSCONVERTER_H

#include "polarphp/ast/DiagnosticConsumer.h"
#include "polarphp/ast/DiagnosticEngine.h"
#include "polarphp/frontend/FrontendOptions.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/Option/ArgList.h"
#include <set>

namespace polar {

/// Implement argument semantics in a way that will make it easier to have
/// >1 primary file (or even a primary file list) in the future without
/// breaking anything today.
///
/// Semantics today:
/// If input files are on command line, primary files on command line are also
/// input files; they are not repeated without -primary-file. If input files are
/// in a file list, the primary files on the command line are repeated in the
/// file list. Thus, if there are any primary files, it is illegal to have both
/// (non-primary) input files and a file list. Finally, the order of input files
/// must match the order given on the command line or the file list.
///
/// Side note:
/// since each input file will cause a lot of work for the compiler, this code
/// is biased towards clarity and not optimized.
/// In the near future, it will be possible to put primary files in the
/// filelist, or to have a separate filelist for primaries. The organization
/// here anticipates that evolution.

class ArgsToFrontendInputsConverter {
   DiagnosticEngine &Diags;
   const llvm::opt::ArgList &Args;

   llvm::opt::Arg const *const FilelistPathArg;
   llvm::opt::Arg const *const PrimaryFilelistPathArg;

   /// A place to keep alive any buffers that are loaded as part of setting up
   /// the frontend inputs.
   SmallVector<std::unique_ptr<llvm::MemoryBuffer>, 4> ConfigurationFileBuffers;

   llvm::SetVector<StringRef> Files;

public:
   ArgsToFrontendInputsConverter(DiagnosticEngine &diags,
                                 const llvm::opt::ArgList &args);

   /// Produces a FrontendInputsAndOutputs object with the inputs populated from
   /// the arguments the converter was initialized with.
   ///
   /// \param buffers If present, buffers read in the processing of the frontend
   /// inputs will be saved here. These should only be used for debugging
   /// purposes.
   Optional<FrontendInputsAndOutputs> convert(
      SmallVectorImpl<std::unique_ptr<llvm::MemoryBuffer>> *buffers);

private:
   bool enforceFilelistExclusion();
   bool readInputFilesFromCommandLine();
   bool readInputFilesFromFilelist();
   bool forAllFilesInFilelist(llvm::opt::Arg const *const pathArg,
                              llvm::function_ref<void(StringRef)> fn);
   bool addFile(StringRef file);
   Optional<std::set<StringRef>> readPrimaryFiles();

   /// Returns the newly set-up FrontendInputsAndOutputs, as well as a set of
   /// any unused primary files (those that do not correspond to an input).
   std::pair<FrontendInputsAndOutputs, std::set<StringRef>>
   createInputFilesConsumingPrimaries(std::set<StringRef> primaryFiles);

   /// Emits an error for each file in \p unusedPrimaryFiles.
   ///
   /// \returns true if \p unusedPrimaryFiles is non-empty.
   bool diagnoseUnusedPrimaryFiles(std::set<StringRef> unusedPrimaryFiles);

   bool
   isSingleThreadedWMO(const FrontendInputsAndOutputs &inputsAndOutputs) const;
};

} // namespace polar

#endif /* POLARPHP_FRONTEND_ARGSTOFRONTENDINPUTSCONVERTER_H */
